Veterinären undersöker pälsen.

Because veterinären is the definite singular form of the noun veterinär.

• en veterinär = a veterinarian / a vet
• veterinären = the veterinarian / the vet

In Swedish, the definite article is usually added as an ending to the noun instead of being a separate word like the in English.

Since veterinär is an en-word, the definite ending is -en:

• en veterinär
• veterinären

Swedish usually puts the at the end of the noun as a suffix.

So instead of:

• English: the veterinarian
• Swedish: veterinären

And instead of:

• English: the fur
• Swedish: pälsen

This is one of the biggest differences from English. In simple sentences like this, Swedish normally does not use a separate word for the.

Undersöker is the present tense of the verb undersöka, which means to examine / investigate.

So:

• att undersöka = to examine
• undersöker = examines / is examining

In this sentence:

• Veterinären undersöker pälsen.
• The vet examines the fur.

Swedish present tense often covers both English examines and is examining, depending on context.

The sentence follows the normal Swedish main-clause order:

• Veterinären = subject
• undersöker = verb
• pälsen = object

So it is:

Subject + Verb + Object

This is the same basic order as in English:

• The vet examines the fur.

Swedish does have the V2 rule in main clauses, which means the finite verb must come in the second position. In this simple sentence, that just gives you normal subject-verb-object order.

Pälsen is the definite singular form of päls.

• en päls = a fur coat / a coat / a pelt / a fur
• pälsen = the fur / the coat

In this sentence, Swedish uses the definite form because it is referring to a specific coat or fur, probably the animal’s fur in context.

Since päls is an en-word, its definite form is made with -en:

• en päls
• pälsen

It can mean a few related things, depending on context.

Common meanings of päls include:

• fur
• an animal’s coat
• sometimes a fur coat as a piece of clothing

In Veterinären undersöker pälsen, it most naturally means the animal’s fur/coat.

So if a vet is doing the examining, pälsen is very likely the animal’s coat or fur, not a human piece of clothing.

The dictionary forms are:

• veterinär = veterinarian, vet
• undersöka = to examine, investigate
• päls = fur, coat

The sentence uses inflected forms:

• veterinären = definite singular of veterinär
• undersöker = present tense of undersöka
• pälsen = definite singular of päls

When learning Swedish, it is very useful to mentally strip words back to their base forms like this.

It is an en-word.

So you say:

• en veterinär
• veterinären

You can also see that päls is an en-word:

• en päls
• pälsen

This matters because en-words and ett-words take different endings and different articles.

A rough guide is:

undersöker ≈ UHN-der-shur-ker or UHN-der-suh-kerr

A few pronunciation notes:

• u in Swedish is not like English u; it is a rounded vowel that many learners find difficult.
• ö is like the vowel in British English bird or fur, but not exactly the same.
• The s/k combination in söker can sound softer than an English sk.

You do not need perfect pronunciation right away, but it helps to notice that Swedish vowels are very important and often different from English ones.

Yes.

The Swedish present tense undersöker can often mean either:

• examines
• is examining

So depending on context:

• Veterinären undersöker pälsen.
  can mean:
• The vet examines the fur.
• The vet is examining the fur.

Swedish does have ways to emphasize an ongoing action, but the simple present is very commonly used where English might choose either simple present or present continuous.

Yes, depending on what you want to emphasize.

This sentence uses:

• pälsen = the fur / the coat

But in a fuller context, Swedish could also specify whose fur it is:

• Veterinären undersöker hundens päls. = The vet examines the dog’s fur.
• Veterinären undersöker dess päls. = The vet examines its fur.

In the short sentence Veterinären undersöker pälsen, the owner of the fur is simply left understood from context.

The indefinite version would be:

En veterinär undersöker en päls.

That means:

• A veterinarian is examining a fur/coat

Compare:

• Veterinären undersöker pälsen. = The veterinarian examines the fur.
• En veterinär undersöker en päls. = A veterinarian examines a fur/coat.

This contrast is a good way to see how Swedish marks definiteness:

• en veterinär → veterinären
• en päls → pälsen